The present invention relates to a toothed wheel or gear with a variable number of teeth.
Such gear mechanisms are known from German Published, Non-Examined Patent Applications DE-OS 21 62 074, DE-OS 18 06 571, from German Letters Patents DE-PS 854 301, 727 593, 142 329 and from French Letters Patents 1 114 218 and 1 295 478.
German Patent Publication DE-A-18 06 571 discloses a single-stage planetary gear, in which the drive chain acts as an internally-geared toothed wheel. This toothed wheel is formed by a drive chain, the length of which is adjustable. A transmission ratio of the planetary gear is changed by changing the length of the drive chain. It has been shown to be disadvantageous that the drive chain is guided only over a few radially adjustable guides distributed over the circumference, so that the gear ring greatly diverges from its ideal circular shape. Therefore this gear can only be used at low rpm and also with high noise output.